Tunnel freezer



Oct. 9, 1951 H. w. KLElsT 2,570,250

TUNNEL FREEZER Filed Oct. 20, 1948 3 Sheets-Sheet 5 Patented Oct. 9, 1951 TUNNEL FREEZER Herman W. Kleist, Chicago, Ill., assigner to Dole Refrigerating Company, Chicago, Ill., a corporation of Illinois Application October 20, 1948, Serial No. 55,44'77 Claims.

My invention relates to an improvement in refrigerating devices, and has for one purpose to provide a unit for freezing articles such, for example, as food.

Another purpose is to provide a material freezing unit in which the articles to be frozen are subjected to sub-zero temperatures and are reduced to sub-zero temperatures in a relatively short time. l

Another purpose is to provide a method for quick-freezing articles of food.

Another purpose is to provide a cabinet assembly which may be readily shipped.

Another purpose is to provide a quick-freezing cabinet assembly which may be shipped in relatively small sub-units, when it is desired to have a completed unit of greater size and length than lends itself to easy packing and shipment.

Other purposes will appear from time to time in the course of the specification and claims.

I illustrate the invention more or less diagrammatically in the attached drawings wherein:

Figure l is an end elevation with the door open;

Figure 2 is a section on the line 2-2 of Figure 5 is a section, on an enlarged scale, on

the line 5 5 of Figure 2;

Figure 6 is a cycle diagram;

Figure 7 is a perspective view of a composite unit; and

Figure 8 is a longitudinal section through the composite unit of Figure 7.

Like parts are indicated by like symbols throughout the specication and drawings.

Referring to the drawings, I generally indicates any suitable supporting surface, such as the floor of a room. A generally indicates an insulated housing having, for example, an insulated bottom wall 2, an insulated top wall 3, and insulated side walls 4 and 5. The details of the insulation do not, of themselves, form part of the present invention, and any suitable insulated cabinet structure may be used. As Will Abe clear from Figures 1 and 2, I illustrate a cabinet which has an opening or interior 6 extending from end to end therethrough, the ends of the opening being closed by any suitable insulated doors 'l and 8 which may be suitably supported, for example, upon hinges 9. In effect, I therefore provide a tunnel of uniform cross-sectional area from end to end, as shown in Figure 7, with any suitable (Cl. (i2- 102) 2 securing means IOI being'employed. When two such units are secured together any suitable gasket may be employed upon or between the abutting ends of adjacent units.

The interior of the housing is divided into a plurality of parallel passages by shelves `in the form of freezing plates; Referring, for example, to Figures 5 and 6, I illustrate a plurality of plates, each of whichris shown as having an upper sheet metal member I5, a lower sheet metal member I6, and a circumferential connecting flange Il, the parts being welded or otherwise secured to provide a substantially gas-proof element. Within the interior of the plate or shelf thus formed I employ cooling coils I8 through which lany `suitable volatile refrigerant may be circulated. The top lplate members or sheets I5 may have upwardly extending side flanges I9. It will be understood that I may employ any suitable securing meansfor supporting a plurality of the shelves in vertically superposed relationship within thecabinet or housing, as shown in Figure 4.' The plates may, if desired, be made removable. and are shown as resting on any securing abutments- 20L I find it advantageous `to cycle a volatile refrigerant'through the'plates in a pair of separate groups, but it will'be lunderstood that any suitable arrangementmay be employed for admitting `a volatile `refrigerant for evaporation Within the coils I8 of the individual plates. I illustrate, `for example, a motor 25 driving any suitable compressor 26 from which compressed refrigerant is delivereditoany suitable condenser 2l and receiver 28. 29 is a high pressure liquid duct with a branch 30. 3|, 32 indicate any suitable pressure reductionv means. 33, 34 indicate the low pressure refrigerant supply ducts extending `to specific plates 35,36. 31 `indicates any suitable connecting passages to connect the plates infgroups, and 38, 39 are return pipes which join at 40and `return to the compressor 26. Whereas this constitutes a satisfactory cycling arrangement, I do not wish to be specifically limited thereto. `1I may, if I wish, provide a less than atmospheric pressure Within the plates. Thus the plates may be partially evacuated through any suitable valvingand sealing means 50, as shown in Figure 3. Thus the walls I5 and I6 are thereafter held by atmospheric pressure in proper heat exchange relationship with the evaporator coils I8. I may also provide an eutectic withinthe plates if I wish, such an eutectic being shown at 5| in Figure 5. It will be understood that the eutectic, frozen by the `upper and a lower freezing plate.

evaporation of volatile refrigerant within the coils i8, serves as a cold storage means.

I provide on one of the doors 8, one or more fans or air circulating devices 60, which may be suitably connected to any suitable source of electricity. Each fan 60 will deliver air along the aligned passages 60a, the air so delivered recirculating 'through the `passages b, which are out of alignment with either fan. It will be understood that, if a plurality of housing units are employed, as in Figure '7, it may be desirable to have fans on each door, or to have the 'plates or shelves of the two units abut at their opposed edges.

Referring to the form of Figures 'I and 8, I illustrate two units, generally .indicated as X and Y,.and which have bottom walls 2, top walls 3 and appropriate side walls. Where two Aunitsare employed the ends are formed 'to abut against reach other, ras shown at -U00, and any suitable .securing means HHV may beemployed forsecuring the Ytwo .members together. `A Vclosure `Il)2..is secured to one end ofone =unit,anda closure 103,

y-rwithfthe appropriate :fans `V60, `is secured to the opposite end of fthe other unit. Asabove pointed ou/t, the freezer plate shelves inthe two units -are formed and 'positioned to approach each jother `along Ythe junction v'Ilm to define the 'fan aligned passages 60a andthe passages 6Ub,which Aare out of 4alignment with the fans, 'and which extend from end to end ofthe unit.

It will be realized that, whereas, I have described and illustrated Ya practical and Yoperative .'device, nevertheless .manychanges maybe made `in the size, shape, .number 4and disposition of Y,parts without departing from the spiritof my invention. I therefore wishmy 'description and .drawings to be taken as-ina broad sense illus- Y.

.trative or diagrammatic, rather `than as limit- ;-ing me to 4my :precise showing.

`The use Aand operation 'of theinvention 'are as '.follows: o

It will be understood that 'the'housing proper may be lmade of `:any desired length. :For example. it mavbem'ade and Aconveniently shipped `in"lengths 'as great as ten feet, or lpossibly Tsomenwhat greater. However, it frnav be advantageous, when ygreater lengths are desired, to make the housing in a plurality `*of separable parts. For example, a plurality of the housings shown in Figure 2 may beplaced end to Aend and suitably lconnected. usingonly the two doors shown in Figure 2 'for the -ends `of Athe entire structure so formed. 'Thus 'a ldouble unit may be provided, Vwhich is open from Iend to -end. As 'amatter of 5 convenience, I Ahave `made the unit -shown in the present drawings open 'fromend toend, 4with the end or door openings-ofthe lsam-e cross section as `the normal intermediate portion of the unit.

Q'Thus by merely removing th'e intermediate doors,

any desired number ofunits, within reason, vmay 'be placed end 'to end and suitably anchored or :locked together, to provide 'a longer length of l travel for the recirculating air. 'Such a structure 1 is shown in Figure '7.

Note .that the interior of the unit shown in Figure 2 is divided into .a plurality of passages j extending from 4 end to end of the unit, each such vpassage being defined between or formed by an .Some of the passages, which are aligned with the fans, receive the direct blast of .air from the fans. The intercontainer.

shelf or inter-plate passages which are not aligned with the fans serve as return ducts for recirculating the air delivered by the fans. The result is that during the use of the device, and when the fans are operating, air is always moving at relatively high speed across all the articles `or .material positioned on any of Vthe shelves or in any of thejpassages. It will be understood that in the use of the device a volatile refrigerant is cycled through the plates. In practice, the recirculation of the air, which is cooled by the plates, cools the material or articles being treated being treated to the desired low temperature.

The structure herein shown may be used fadivantageously within a space where the ambient temperature is considerably higher than the temperature within the housing. I therefore 'find it advantageous to provide a heavily insulated Whereas I illustrate, in Figure 2, a housing with a door at veach end, it will be understood that the inner end of the unit may, under some circumstances, be vpermanently closed. However, Iii-ind it practical to provide a door at each end of the unit, with lblowers preferably mounted on one door only.

It will be understood that Where multiple units are employed the evaporator coils of the shelves of the individual units may be connected in any suitable manner to the cycling mechanism. Whereas, in the diagram of 4Figure 6, I illustrate the shelves vof a single unit separated into two groups, it will be understood that the shelves of each unit .may Iform an individual group, the cycling diagram being the same, as shown in Figure 6, except for an increase in the number of plates in each individual group. It will be further understood that any other suitable means -or arrangement for connecting the plates to the compressor-condenser unit may be employed.

I claim: Y

1. In a refrigerating device for freezing Ina-- terialsa cabinet having walls'of insulatingmaterial dening an open-ended passage, normally stationary shelves in said passage defining a plurality of parallel inter-shelf ducts, said shelves having end edges spaced inwardly from the ends of the passage, vsaid shelves having evaporator coils for the evaporation of a volatile refrigerant, closures for the ends of the passage, and air circulating means aligned `with some of the intershelf ducts and out of alignment with others of vthe inter-shelf ducts, said latter ducts constituting return passages for the circulated air.

2. The structure of claim 1 characterized in that the air circulating means includes an air circulating fan mounted on the closure for one end of the passage.

3. The structure of claiml characterized in that the air circulating means includes a plurality of fans mounted on the closure for one end of the passage.

4. In a refrigerating device for freezing materials, a plurality of cabinet units, each such unit having walls of insulating material den- .ing an open-ended passage, means for securing together tWo `opposed open ends of a plurality .of

such units, closures for the ends of the openended passage thus formed, normally stationary shelves in said passage defining a plurality of parallel inter-shelf ducts, and air circulating means aligned with some of the inter-shelf ducts and out of alignment with others of the intershelf ducts, said shelves having evaporator coils for the evaporation of a Volatile refrigerant.

5. The structure of claim 4 characterized in that freezer shelves are located in both units, the individual freezer shelves in each unit being aligned with and terminating adjacent corresponding shelves in the other unit.

HERMAN W. KLEIST.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS 

